Fix lightgallery version to fix #53.

There seems to be a breaking change between 1.2.14 and 1.3.5
where light gallery doesn't bundle-in the plugins.
Instead they're available for download as separate npm modules.

Will need to fix that if we want to upgrade to the latest version of lightgallery.

package.json

@@ -32,7 +32,7 @@
     "gm": "^1.23.0",
     "handlebars": "~4.0.5",
     "less": "^2.7.1",
-    "lightgallery": "^1.3.5",
+    "lightgallery": "1.2.14",
     "lodash": "^4.16.6",
     "moment": "^2.16.0",
     "pad": "^1.0.2",